Diego Simeone is hopeful Joao Felix has just suffered a knock after he was forced off in the second half of Atletico Madrid's win over Elche.
LaLiga leaders Atletico won 3-1 at Wanda Metropolitano on Saturday, with Luis Suarez scoring twice for the hosts.
Forward Joao Felix limped off to be replaced by the returning Diego Costa with 17 minutes to go.
Costa duly wrapped up the victory by winning and converting a late penalty, settling any brief nerves caused by Lucas Boye scoring a header for Elche.
"The blow [Joao Felix took] in the first half was strong and hard," Simeone said about the 21-year-old after the match.
"It was in the play in which they stopped the counter-attack with the block on Joao - he was still playing in the second half with discomfort and pain.
"I saw him working very well for the team despite being uncomfortable, but after he took a shot at goal it was noticed that he was upset.
"Let's hope it's just a knock - we understood [it would be wise] to let him rest. The game was getting complicated and we needed legs in that area of the pitch."
Suarez had gone three games without a goal before scoring the match-winning double in his 200th LaLiga appearance.
Simeone had taken the blame for the striker's dry spell ahead of the match because he put him straight back into the team after a spell out with coronavirus.
The Atletico boss added: "We understand that all players need personal treatment, because the character of each one is different.
"It's like children in families and each one is handled, like with the five I have, in a different way.
"I didn't say anything strange about Luis, he played three games in a row last week when he was coming off a 20-day break.
"I was especially happy with the second goal, he waited until the last possible moment so he did not stray offside and made sure he could be found after a good piece of play by Yannick Carrasco."
Since making his LaLiga debut in October 2014, only Barcelona's Lionel Messi (36) has scored more braces in the competition than Suarez (23).